This is a roof purline building built by Gen-emon Tsushima (Osamu Dazai’s father), who was a large landowner during the Meiji Era. Work was completed in June 1907. Cypress wood was used for all structures, including the rice storehouse. It has 11 rooms with an approximate area of 917 square meters on the first floor, and 8 rooms with an approximate area of 383 square meter on the 2nd floor. It is a grand mansion extending over an area of approximately 2244 square meters, with attached buildings and a Japanese garden with ponds.